Reel stop and drive



Dec. 23, 1952 w. A. BRASTAD 2,622,812

REEL. STOP AND DRIVE Filed March 22, 1947 FIG. I

66 IN VEN TOR WILLIAM A. BRASTAD Patented Dec. 23, 1952 REEL STOP AND DRIVE William A. Brastad, Minneapolis, Minn, assignor to General Mills, Inc., a corporation of Delaware Application March 22, 1947, Serial No. 736,523

6 Claims.

This invention relates to means for driving reels in a sound-on-wire recorder-reproducer in either direction to wind them in one direction for recording or reproducing and in the opposite direction to rewind.

An object of the invention is to provide means for stopping the machine just before the driven reel is unwound so as to prevent the wire end from becoming free, resulting in a tangle on the full reel and requiring re-threading in the machine if the wire is to be rewound on the empty reel.

Another object is the provision of means for manually controlling the operation of the motor near the empty end of either reel.

These and other objects, as will hereinafter appear, are fully described in the following specification and shown in the accompanying drawings in which Figure l is a diagrammatic view partly in section and partly in elevation, shOWing a preferred form of the invention;

Figs. 2 and 3 are transverse sections on the lines 2- and 3 respectively of Fig. 1; and

Fig. 4 is a partial enlarged section on the line l of Fig. 1.

The embodiment illustrated comprises reels I0, I2 for carrying wire on a sound-on-wire recorderreproducer. These reels are removably mounted on hollow shafts It, It, which in turn are journalled in suitable bearings not shown.

On the shaft I4 is keyed a pulley 20, and a pulley 22 is similarly keyed on a shaft IS opposite the pulley and spaced therefrom. A friction drive pulley 26 is mounted on a shaft 28 of the motor 30 which is mounted on a base 32 which is slidable back and forth by means of slots on pins 42, so that the drive pulley 26 can make contact either with the pulley 22 or pulley 20 as the base 32 is shifted to the right or to the left as will be explained.

Referring now to Fig. 4, the shaft 42 is journalled in a panel 25 of Bakelite and carries a rocker lever which has an extension 52 sliding in a notch E l in the base 32. The shaft M has a knob 56 securely mounted thereon and by which the shaft is oscillated so as to oscillate the base 32, motor 30, and drive pulley 25 to cause the latter to contact either of the pulleys 29 or 22.

To make sure that these parts will stay in the adjusted position, I have provided a circular slide 60 engaging a cylindrical lower end 62 on the lever 50, and this is slidable on an arm 64 mounted on a pin 66 carried by the panel 46. A spring 70 urges the slide 60 outwardly and the movement of the knob 56 is such as to cause the lever 52 to pass through dead center so that the spring 10 tends to hold the lever 50 to the right or to the left of center according to which way it is switched by means of the knob 55, thereby holding the drive pulley 26 in contact with the pulley 22 when the motor 30 and base 32 are shifted to the right as shown in Fig. l, and in contact with the pulley 20 when the motor is shifted to the left.

Each of the shafts I4 and it have secured thereon a hollow cylindrical block 80, adapted to receive the lower end of a hub 82 on the reel and which carries a pin 84 adapted to fit into a hole 86 in the end of the hub 82.

The lower end of the hub 82 is provided with a slight annular recess 9%) and an upper end of the block is grooved on both sides at 92 to receive a spring clip EM which is adapted to engage the recess 90 to yieldably retain the reel on the end of the shaft.

The block 80 is provided with a lateral arm 8 I, Figs. 1 and 2, the latter being bifurcated to receive a bell-crank I [I0 which is pivotally mounted at I82, the inner end being slidably mounted in a recess IM in a pin lit. The opposite end of the bell-crank terminates in a finger I08 which lies in a recess i It) in the reel when the pin 84 is in the hole 86.

The pin I66 is slidable within the hollow shaft It (and the same construction is duplicated in shaft I5), and engages a switch lever I20 pivotally mounted at I22 and normally held upwardly by means of a spring I24. This lever engages the operating pin of the micro-switch I25.

A similar pin Illl operates switch lever I2I which is normally held up by means of a similar spring I25. The switch lever I2! operates the pin of a similar micro-switch I2i.

The micro-switch I25 connects with one side of the electric powerline L, thence through a lead I30 with the micro-switch i2l, thence through a lead I32 with the motor Bil, thence through a lead I34 to a line switch S and thence to the other side of the powerline L.

The finger I28 is each case is so proportioned with respect to the micro-switch to which it is connected, that when a number of turns of wire W are wound over the finger H93, the pin I06 will be depressed to the point that the microswitch I26 will be closed. When, however, the last few turns of wire are unwound, they release the finger N18 with the result that the spring I24 retracts the lever I20, opening the micro-switch and stopping the motor. In this case, it will be noted that the opposite reel I2 is now filled with wire and consequently the micro-switch I2! is held closed.

Some satisfactory means for preventing overrun of the reel from which the wire is being unwound must be used. Since the motor, having considerable kenetic energy at th instant that the current is stopped, continues to drive the take-up reel, only a fixed frictional drag on the unwinding reel shaft is necessary to prevent overrun. Another solution to this problem would be brakes automatically applied to the reel shafts when th motor current is interrupted.

Should the operator now wish to rewind the wire from the full spool to the empty spool, he could not do so by merely closing the switch S. In addition, it would be necessary momentarily to close the micro-switch I26. This he can now do by manually depressing its pin W6 and holding it down until a few turns of wire have been wound over the end of the finger I538. After that, this pin can be released. It .will be understood, of course, that in order to make this reversal, it is first necessary to shift the motor 32 by means of the knob from the right side where it is now shown, into contact with the pulley 20.

Should the operator wish to put in a different reel of recording medium; he may rotate the full reel by hand to wind the few remaining turns. The reels can be removed from the shafts by a slight pull. As the new full reel is being pushed down to engage the retaining spring clip 94, the manual pin 196 must be pressed to draw in the finger :58 so that the-reel full of wire can slide completely into position. Depressingpin I88 does not start the motor because the automatic switch on the other shaft is still open.

An empty reel can be slipped on this second shaft without retracting the finger suchas I68 since there are no coils of wire to prevent proper engagement of the reel with the finger in it extended position. After the wire has been suitably anchored, the-motor may beenergized by pressing the second manual pin, provided the line switch-S is in the closed position.

After a few turns of wire have been wound over the end of the finger such as 35, manual pressure on the pin is obviated. An advantage of the manual pin is that the initial retraction of the finger such as N38 is not dependent upon wire tension.- After several turns have been wound over the recess ass, ample force is available. to hold in the finger.

Thus, it will be seen that I have provided a very simple and efficient means for preventing either reel from completely unwinding with the attendant tangle which is very likely to ensue in the last turns of this steel wire which is very stiff and easily tangled.

While I have shown anddescribed out a single embodiment of invention, it is to be under.- stood that it is capable of many modifications. Changes, therefore, maybe made which-do not depart-from the spirit and scope of my invention as disclosed in the appended claims.

I claim as my invention:

1. In a machine of the class described, two reels, two shafts, each adapted to hold a reel and to drive the electric motor means for alternately driving each shaft so as to wind a wire on the driven reel and to unwind from the other reel, a finger carried to rotate with each reel, a spring tendingto press the finger outwardly when all but the last few turns of wire have been unwound from the reel, a switch connected in circuit with the electric motor and operable by said finger to stop the motor when said finger moves outwardly, and a push rod operably connected to said switch and said finger for manually controlling said switch to operate the motor to start the winding of a reel. or to finish unwinding it and for drawing said finger inwardly.

2. In a machine of the class described, two reels, two hollow shafts, each adapted to hold a reeland. to drive the same, electric motor means for alternately driving each shaft 50 as to wind a wire on the driven reel and to unwind from the other reel, a finger carried with each reel, a spring tending to press the finger outwardly when all, but the last few turns of wire have been unwound from the reel, a switch in circuit with the electric motor, and a push rod slilably mounted in one of the shafts and operably connected to said switch andtoitscooperating finger for manuallycontrolling said switch to start the winding of a reel-or to finish unwinding'it, said finger being operably connected to said push rod to cause the switch to close as'the finger moves-inwardly and t open as the finger moves outwardly.

S. In a machine of the-class described; two reels, twoparallelholow shafts, each-adapted to hold a reel'andtodrive the same, electric motor means for alternately driving each shaft so as to wind a wire on the driven reel and to unwind from the other reel, a finger carried witheach reel, a spring tending, to press the finger outwardly when all but the last few turnsv of wire have been unwound from the reel, two switches connected to the electric motor in series'circuit, a push rod slidably mounted in each of the shafts and each operable to open and close a separate switch, spring means'tending toopen said switches, each finger beingoperably connected to one of the push rodsand extending into a recess in its reel so that some of the first turns of wire on the reel operate throughthe finger and push rod to hold that switchclosed.

i. In a machine of the class described, two reels, two shaft assemblies each adapted tohold a reel and to drive the same, electric motor means for alternately driving each shaftso as to' wind a wire on the driven reel and to unwind from the other reel, 2. finger mounted adjacent the-reel, a spring tending to press thefinger outwardly when all but the last few turns of wire have been unwound'from the reel, a switch'operably connected to the finger controlling the electric motor circuit to stop, the motor when'the reel becomes unwound and-said finger moves outwardly; anda manually operating rod extending to a pointremote from the operating elements and connected to said finger for manually moving said finger inwardly and controlling said switch to start the winding of a reel or to finish unwinding it.

5. In a machineof the class described, an assembly including a rotatable reel upon which wire may be wound and having a hole therethrough coaxial with the reel, means for unwinding the wire from the reel, drive means selectively operative to rotate the reelin a direction to wind the wire or to drive said unwinding means, control means situated on one side of the reel and adapted to start or stop the drive means, a rod connected to and extending from the control mean through the hole in the reel to the side of the reel opposite the control means, said rod being manually operable to start the reel, and means connected to the rod and responsive to the emptying of the reel to stop the drive means.

6. In a machine of the class described, a rotatable assembly upon which a first reel is mounted for winding recording wire thereon, said reel having a hole therethrough extending coaxial with the axis of rotation, a drive means operable to rotate the reel, 2. second reel rotatable to unwind the Wire from the first reel, means operative upon the emptying of the first reel to stop the second reel, and a manually operated push rod coaxially mounted in the hole in the reel and operatively adapted to start the drive means to wind the wire on the first reel.

WILLIAM A. BRASTAD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS France Nov. 9, 1939 

